[Diy_efi] O2 sensor location

[Ashley Wagner]

Hello, I have been running a heated O2 sensor at the collector of a  
long tube header. The header is on a 76 chevy PU and the tubes extend  
below the chassis into the airflow. During the day the everything  
works very well, but at night when the temp drops my wideband  
readings become very lean. (the wideband is only for datalogging) I  
am thinking that my O2 sensor is cooling off from the airflow  
surrounding it and giving faulty values to the ecm, it is a heated O2  
sensor. Has anyone had similar issues and other than replacing the  
header does anyone have a suggestion to remedy the problem?
	7747 ecm and TBI system
							Thanks for your time

								Ash